Conditional Proxy Re-Encryption Secure against Chosen-Ciphertext Attacks

Publication Type

Conference Proceeding Article

Publication Date

2-2009

Abstract

In a proxy re-encryption (PRE) system [4], a proxy, authorized by Alice, can convert a ciphertext for Alice into a ciphertext for Bob without seeing the underlying plaintext. PRE has found many practical applications requiring delegation. However, it is inadequate to handle scenarios where a fine-grained delegation is demanded. To overcome the limitation of existing PRE systems, we introduce the notion of conditional proxy re-encryption (C-PRE), whereby only ci-phertext satisfying a specific condition set by Alice can be transformed by the proxy and then decrypted by Bob. We formalize its security model and propose an efficient C-PRE scheme, whose chosen-ciphertext security is proven under the 3-quotient bilinear Diffie-Hellman assumption. We further extend the construction to allow multiple conditions with a slightly higher overhead.

Discipline

Information Security

Research Areas

Information Security and Trust

Publication

Proceedings of the 4th International Symposium on Information, Computer, and Communications Security (ASIACCS '09), Sydney, Australia, March 10-12

First Page

322

Last Page

332

ISBN

9781605583945

Identifier

10.1145/1533057.1533100

Publisher

ACM

City or Country

Sydney, Australia

Additional URL

http://dx.doi.org/10.1145/1533057.1533100

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